Download engines and tool updates

What each tool does

yt-dlp is the primary media downloader. FFmpeg processes and converts audio/video, while FFprobe reads media details. They are managed as one pair. Deno supplies JavaScript support needed by some YouTube downloads. pytubefix is an optional YouTube-only backup, not a replacement for yt-dlp across other sites.

Install or update in Tools

1. Open Tools and choose Check for updates. Read the installed and available versions on each card.
2. Use Update all for outdated tools, Install missing for missing tools, or an individual tool’s button. Install missing includes the optional backup when it is missing.
3. Tools are processed in sequence. Cancel remaining work if needed, or use Retry failed after resolving an error.
4. On macOS and Linux, FFmpeg and FFprobe are updated with Loaderly. Follow the card’s app-update guidance for that pair.

Choose Automatic or a specific engine

1. Install pytubefix from its Tools card if you want a backup. No separate setup is needed outside Loaderly.
2. Open PreferencesDownloads > YouTube download engine. Choose Automatic for yt-dlp first, yt-dlp to use only the primary engine, or pytubefix to request the backup for YouTube.
3. In Automatic, an installed backup is tried once when a supported YouTube download fails. Other sites and reading YouTube playlists still use yt-dlp.

Switching engines does not bypass sign-in, access or rate-limit restrictions. Cancellation, disk and permission errors do not trigger automatic fallback. Both engines can be affected by changes on YouTube.

Recover from an installation failure

1. Expand the error details on the failed tool’s card. Check the connection, disk space and any indicated permissions.
2. Retry that tool or Retry failed. A failed update preserves the previous working version when one exists.
3. For support, include the displayed error and app/tool versions. Review local diagnostic details before sharing them. They can contain local paths.